Re: Re: [COMMITTERS] Can not create more than 32766 databases in ufs file system.

* Mark Mielke (mark(at)mark(dot)mielke(dot)cc) wrote:
> There is no technical requirement for PostgreSQL to separate data in
> databases or tables on subdirectory or file boundaries. Nothing wrong
> with having one or more large files that contain everything.

Uhh, except where you run into system limitations on file size (eg- a 2G
max file size..). You'll note PG creates files up to 1G and then splits
them into separate files. It's not done just because it's fun.

> I guess I'm not seeing how using 32k tables is a sensible model.

For one thing, there's partitioning. For another, there's a large user
base. 32K tables is, to be honest, not all that many, especially for
some of these databases which reach into the multi-TB range..

> So yes,
> things can be done to reduce the cost - but it seems like something is
> wrong if this is truly a requirement.

I have no idea what you've been working with, but I hardly think it
makes sense for PG to consider over 32k tables as not worth supporting.

> There are alternative models of
> storage that would not require 32k tables, that likely perform better.

Eh? You would advocate combining tables for no reason other than you
think it's bad to have alot?

> Do you agree with me that having 32k open file descriptors (or worse,
> open on demand file descriptors that need to be re-opened many times) is
> a problem?

Nope.

> Looking at PostgreSQL today - I don't think it's designed to scale to
> this. Looking at SQL today, I think I would find it difficult to justify
> creating a solution that requires this capability.

Actually, I find that PG handles it pretty well. And we used to be an
Oracle shop.

Thanks,

Stephen